The present invention relates to a method for controlling a drive device of at least one partially electrically driven vehicle, having at least two vehicle wheels mechanically coupled by way of respective electric drive units, wherein the electric drive units each receive electrical energy during motor operation from an electrical energy storage device and/or supply electric energy during generator operation to the energy storage device, wherein the electric drive units provide in normal operation a torque in accordance with an drive-unit-specific target torque of a vehicle control system. The invention further relates to a vehicle control system and a vehicle with the vehicle control system.
Vehicles of the generic type are known in principle, so that a specific documentation is not required. Vehicles, also known as motor vehicles, are used to travel on land. When in addition to an electric machine as a drive, a combustion engine is additionally provided as a drive, these vehicles are usually referred to as hybrid vehicles. A vehicle having a drive device composed exclusively of one or more electric machines is typically referred to as an electric vehicle. The electric machines used for generic vehicles can usually be rotating electric machines, for example, a DC machine, a three-phase machine, or the like.
For driving operation, the electric machine(s) is/are electrically connected to a battery of the vehicle. The battery is generally designed as a high-voltage battery and supplies a maximum current, which can be consumed by the electric machines. A portion of this maximum electric current is transmitted to the respective electric machine. A controller associated with the respective electric machine computes from the value of this current a minimum or maximum torque that can be attained by the respective electric machine by supplying this maximum current. These maximum torques determined from the power provided to the electric machines are transmitted to a vehicle control system of the vehicle.
By using the vehicle control system, a drive target torque set by a driver of the vehicle is divided among the available electric machines in accordance with the maximum torques of the electric machines. This ensures that the maximum current of the vehicle battery is not exceeded, thus preventing an impermissible operating state of the vehicle battery.
Although this approach has proven effective, it is disadvantageous that individual electric machines cannot be operated above their assigned power, even if the vehicle battery can still provide energy reserves. In addition, the vehicle control system does not have a feedback from the respective inverter with respect to the torque setting range that is actually available. Both the inverter and the electric machine can typically be operated at least temporarily at a higher power than the assigned power.